Abstract:

With the increasing of mining depth，the mine ventilation systems become more and more complex， working face location farther away from the main ventilating fan of the earth’s surface than they are used to be，the main ventilating fan of the earth’s surface can not supply much air to the deep of underground.And it could barely control the deep ventilation.Therefore，it is needed to move the fan into the underground.After the fan is installed in the underground，these could have shorten the distance from the ventilation fan to the working face location.However，these have increase more recirculating air.In order to achieve effective ventilation，ensure the deep of underground could get enough air，the problem of the recirculating air must be effectively controlled.Actually the essence of internal air leakage is the existence of the recirculating air in ventilation system.This paper aims to analyze the formation of recirculating air，propose the evaluation indexes of internal air leakage in ventilation system and develop the software-VentNetLab to get effective control measures.And the evaluation indexes-the efficiency of adjustment could be used to evaluate complexity of mine ventilation adjustment. Multi-level stations ventilation must be used by various mine to achieve effective ventilation.This can carry on the research for the extremely complicated ventilation network，and guidance for rectification mine.

Key words: complex mine, recirculating air, efficient ventilation, empirical study